copy data from multiple sheets to one and update inventory

hello
i have many sheets " purchase , sales, returns sales ,returns purchase " every in voice in theses sheets should copy to sheet data i put the result in sheet data and at the same time updating the inventory in sheet stock it should subtracting the quantity from "sheets sales " &" returns purchase " and add to the quantity from sheets " returns sales " and " purchase "
if my post is not clear please tell me
thanks in advance